A great new article from a collaboration between Dr. Jeff Weiss's lab and our founder, Dr. Michael Yu's lab at the University of Utah. The new Acta Biomaterialia paper explores at what point collagen denaturation occurs in tendons under mechanical strain and how tendon type influences the mechanism of failure. Researchers evaluated functionally distinct tendons using positional tendons (rat tail tendons) and energy-storing tendons (rat flexor digitorum ...
Fig. 1. Study overview. (A) Rat tail tendon fascicles were loaded in creep-fatigue to 40% of the ultimate tensile strength (UTS) until tissue failure. Incremental levels of fatigue were defined as the peak cyclic (creep) strain at 20, 50, and 80% of cycles to failure. (B) To label and quantify denatured collagen, we stained mechanically loaded fascicles with fluorescent CHP, which hybridizes to unfolded collagen ? chains. The amount of denatured collag...
In this interesting article published in Bone, researchers from Penn State utilized CHPs to help monitor fracture healing in the diet-induced obesity (DIO) mouse model. They applied numerous characterization techniques to probe the microstructure of collagen within a wound (fracture) healing environment. They evaluated collagen structure in a healthy (lean) mouse model and compared it with the DIO model using second harmonic generation (SHG), micro-CT, ...
Extra! Extra! Read all about it! In a recent publication in the Journal of the Mechanical Behavior of Biomedical Materials, researchers from Dr. Diane Wagner's lab from Indiana evaluated the anisotropy of cartilage in an accelerated in vitro cartilage wear test. They found that CHP staining of damaged collagen highlighted that transverse (orthogonal) loading caused greater damage to collagen than with longitudinal loading. This was not due to increased ...
A new article published in the Journal of the Mechanical Behavior of Biomedical Materials used F-CHPs (Figure 7) to assess the damage in an intervertebral disc (IVD) model. Researchers used CHPs to help validate their new mouse disc organ culture system by dynamically applying compression loading in a customized micro-culture device tailored for mouse lumbar discs. They tested native, static, and loaded discs to see how mechanical damage affects disc he...
Interesting work done in Jess Snedeker's lab was recently published in Matrix Biology. This work evaluated how microdamage to rat tail tendon fascicles influenced the ability of tenocytes (tendon fibroblasts) to aid in repair. This was probed by stretching fascicles up to 8% strain, using CHPs to stain for collagen damage, and then looking at the functional recovery of the fascicles up to 7 days after initial strain. They also looked at cell viability u...
Exciting work published in Soft Matter utilized F-CHPs to analyze molecular damage to collagen fibrils after a single asymmetrical stretch-release experiment. Researchers saw that the supramolecular fibril structure was unaffected by these experiments and that a fibril rupture is not a pre-requisite for molecular denaturation of the collagen fibril. The figure below shows how the asymmetrical stretch-release experiment was performed. The dotted line re...
New work being done by Dr. Robert Mauck's Lab at UPenn utilized CHPs to examine the effect that fatigue loading has on localized tissue mechanics. Their team discovered that although fatigue loading resulted in collagen kinking and denaturation, there was no difference in the local tissue modulus when compared to fresh controls. The image below shows how CHPs were used to visualize the collagen denaturation from fatigue loading and compare with the fres...
A recently published paper in the Journal for Orthopaedic Research utilized F-CHP to develop a microplate assay for quantifying the amount of denatured collagen in samples. The authors compare their newly developed microplate assay with the hydroxyproline assay which is commonly used to determine the collagen content in a digest. They show that with the F-CHP, their new assay was just as accurate as the hydroxyproline assay but required much less time ...
Are you interested in evaluating the mechanical damage of tissues or evaluating how collagen damage influences mechanical properties?? Well, then this paper is for you! A new article published in The Journal of the Mechanical Behavior of Biomedical Materials shows that CHPs can help give quantitative information regarding the damage to collagen fibers at a molecular level. The authors explain how this molecular-level damage influences the mechanical pr...
